1 min. 2kV 50% for 15 sc
Shaft. BIR 761055
(signature) Surveyor to Lloyd’s Register of Shipping.
Hot insulation High voltage test resistance (megohms) 100 volts AC for Identification marks No. 51433/1 Lloyd's Test Lon (port)
RAL/initials 13.12.84 (dale)
Fee 79.60 Expenses 1.70
Prior to the commencement of supervising the manufacture of the electrical equipment the following documentation is to be submitted for consideration: 1) description of the principle of operation and main characteristics; 2) material specification (list ol products) which is to contain elements, instruments and materials used and their technical characteristics; 3) assembly drawing with sections; 4) circuit diagram;
5) test programme; 6) mechanical rotor shaft calculations, as well as drawings of fastening of poles, magnetic circuit stackings, commutator, etc., and detailed drawings of elements welded to the shaft; 7) for distribution switchboards — calculation of thermal and electrodynamic strength of busbars under short-circuit conditions and choice of apparatus to fit these conditions where current rating of a generator or generators running in parallel exceeds 1,000 A.
The sixth class period
Listen carefully to the recorded (ext. What distinguishes these two texts?
Resistors
A resistor is one of the most common elements of any circuit. Resistors are used: 1) to reduce the value of current in the circuit, 2) to produce 1R voltage drop and in this way to change the value of the voltage.
When current is passing through a resistor its temperature rises high. The higher the value of current the higher is the temperature of a resistor. Each resistor has a maximum temperature to which it may be heated without a trouble. If the temperature rises higher the resistor gets open and opens the circuit.
Resistors are rated in watts, since P = EX 1 — RXRX1 = 1>2R, where P — power, is given in watts, R — resistance, is given in amperes.
If a resistor has a resistance of only 2 ohms but its current-carrying capacity equals 2,000 ampere, it is rated as a 8,000,000-W resistor.
Some resistors have a constant value — these arc fixed resistors, the value of other resistors may be varied —these are variable resistors.
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Resistors can be grouped into three basic classes: composition type resistors, film-type resistors, and wirewound resistors. As the name implies, composition resistors are molded rods made from a powdered and electrically conductive mixtures of graphite and an inert plastic binder. Wirewound resistors consist of a wire or metallic ribbon wrapped